1. Field of the Invention
The present invention relates to a portable electronic device and a method for waking up the same from a sleep mode. More particularly, the present invention relates to a portable electronic device and a method for waking up the same from a sleep mode through a touch screen.
2. Description of Related Art
With a quick development of technology, most of portable electronic devices apply a touch screen to improve an operation convenience thereof. Presently, the touch screens are approximately grouped into resistive touch screens, capacitive touch screens, infrared touch screens and ultrasound touch screens, etc. Since the resistive touch screen has a low cost, and a technique development thereof is relatively mature, it becomes a mainstream in development of the market.
FIG. 1 is a block diagram illustrating a conventional electronic device having a touch screen. Referring to FIG. 1, the electronic device 100 applies a touch screen controller 120 to control a resistive touch screen 110. In a normal operation mode, the touch screen controller 120 may send a plurality of scanning voltages to the resistive touch screen 110 to detect a coordinate value of a touch point. Moreover, a central processor 130 receives a read signal IN11 from the touch screen controller 120, and reads the coordinate value VL1 stored in the touch screen controller 120 to perform a corresponding operation.
On the other hand, when the central processor 130 enters a sleep mode, it can only be waked up and switched to the normal operation mode in response to an enabling signal IN12 sent from a physical key 140. The central processor 130 may send an enabling signal IN13 to the touch screen controller 120 for waiting to read the coordinate value VL1 only when the central processor 130 is in the normal operation mode. In other words, in the sleep mode, a user has to first press the physical key 140 to wake up the central processor 130, and then the central processor 130 can read the coordinate value VL1 stored in the touch screen controller 120 to perform the corresponding operation.
It should be noted that in recent years, various electronic products have a general development trend of easy operation, small-size and large screen size, and especially for the portable electronic device, a requirement for a volume and the screen size thereof is more strict. Therefore, in a plenty of the electronic products, the touch screen and a liquid crystal panel are integrated to save a space originally used for containing a keyboard or the physical key, so as to enlarge a configurable area of the screen. However, regarding a conventional electronic device, while the screen size thereof is expended, a hardware space of the physical key has to be maintained, so as to facilitate waking up the central processor. In this case, not only the features of the small size and the large screen size of the electronic device are hard to be achieved, but also a usage complexity of the touch screen is increased.